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kernel/kernelmq/tss.c

87 lines
2.3 KiB
C

#include "tss.h"
#include "config.h"
#include "stdlib.h"
struct gdt_entry_bits {
unsigned int limit_low : 16;
unsigned int base_low : 24;
unsigned int accessed : 1;
unsigned int read_write : 1;
unsigned int conforming_expand_down : 1;
unsigned int code : 1;
unsigned int always_1 : 1;
unsigned int DPL : 2;
unsigned int present : 1;
unsigned int limit_high : 4;
unsigned int available : 1;
unsigned int always_0 : 1;
unsigned int big : 1;
unsigned int gran : 1;
unsigned int base_high : 8;
}
__attribute__((packed));
struct tss_entry {
unsigned int prev_tss;
unsigned int esp0;
unsigned int ss0;
unsigned int esp1;
unsigned int ss1;
unsigned int esp2;
unsigned int ss2;
unsigned int cr3;
unsigned int eip;
unsigned int eflags;
unsigned int eax;
unsigned int ecx;
unsigned int edx;
unsigned int ebx;
unsigned int esp;
unsigned int ebp;
unsigned int esi;
unsigned int edi;
unsigned int es;
unsigned int cs;
unsigned int ss;
unsigned int ds;
unsigned int fs;
unsigned int gs;
unsigned int ldt;
unsigned short trap;
unsigned short iomap_base;
};
static struct tss_entry tss;
void tss_write_to_gdt(const struct KernelMQ_Info *const kinfo, void *gdt_entry_ptr)
{
struct gdt_entry_bits *const g = gdt_entry_ptr;
unsigned long base = (unsigned long)&tss;
unsigned long limit = sizeof(tss);
g->limit_low = limit & 0xFFFF;
g->base_low = base & 0xFFFFFF;
g->base_high = (base & 0xFF000000) >> 24;
g->limit_high = (limit & 0xF0000) >> 16;
g->accessed = 1;
g->read_write = 0;
g->conforming_expand_down = 0;
g->code = 1;
g->always_1 = 0;
g->DPL = 3;
g->present = 1;
g->available = 0;
g->always_0 = 0;
g->big = 0;
g->gran = 0;
kmemset(&tss, 0, sizeof(tss));
tss.ss0 = GDT_KERNEL_DS_SELECTOR;
tss.esp0 = kinfo->kernel_stack_top;
}